Murphy Switch A20 Series User Manual

AT-95026B  
Revised 08-05  
A20 and A25 Series  
Catalog Section 10  
Temperature SWICHGAGE®  
2 and 2-1/2 in. (51 and 64 mm) Dial  
**  
Corrosion Resistant Polycarbonate Case  
Indicating Gage and Limit Switch  
Switch Can Activate Alarms and/or Shut  
Down Equipment  
Critical/High Temperature Limit Switch  
Is Visible and Adjustable (Most Models)  
A20T Series  
shown  
Contact(s) Isolated From Ground  
Case: Glass filled/Polycarbonate, corrosion-resis-  
tant; steel mounting clamp included. Bezel:  
Polished stainless steel, standard; others  
are available.  
®
A20TL and A25TL SWICHGAGE  
For use on Ford Worldwide engines. Supplied with  
special sensing bulb.  
Description  
The A20 Series (2 inch/51 mm dial) and the A25  
®
Series (2-1/2 inch/64 mm dial) SWICHGAGE mod-  
els are diaphragm-actuated, temperature-indicating  
gages, with built-in electrical switches for tripping  
alarms and/or shutdown devices.  
®
A20TE and A25TE SWICHGAGE  
Pointer: Tempered nickel silver; red tip.  
Lens: Polycarbonate, high-impact.  
A20TE (was A20ESR) and A25TE (was A25ESR).  
Models with internal SPDT snap-switches, instead  
of the single pole/pointer contact(s). When the  
switch closes on rising temperature, it becomes Set.  
As temperature decreases the switch Resets.  
Model A25TE is CSA listed for  
Ranges are available from 32-120°F (0-45°C) thru  
Sensing Element: Beryllium copper diaphragm.  
300-440°F (160-220°C).  
Capillary: PVC armored copper; 4 ft. (1.2 m)*.  
All models of these rugged, built-to-last instruments  
are fully sealed from the environment by the unique  
combination of a polycarbonate case and lens, a pol-  
ished stainless steel bezel, and O-ring seals.  
Stainless steel armor optional.  
Sensing Bulb: Copper*.  
non-hazardous areas. Model  
Gage Accuracy: See accuracy chart, on page 2.  
A25TE-EX is CSA listed for  
Maximum Temperature: See Temperature Ranges  
Class I, Division 1, Groups  
These vapor/pressure actuated gages feature a sealed  
capillary tube and a sensing bulb. When subjected to  
heat, the liquid in the sensing bulb changes to vapor  
creating pressure against a diaphragm mechanism.  
The diaphragm translates this vapor pressure into a  
mechanical gage reading.  
and Factory Settings table on page 2.  
C & D hazardous areas.  
Adjustable Limit Contact (A20T and A25T):  
SPST contact; pilot-duty only, 2 A @ 30 VAC/  
VDC; isolated from case ground. Normally Closed  
when the high limit is met. Normally Open when  
pointer is in normal operating range. Contacts are  
gold flashed silver.  
®
A20TABS and A25TABS SWICHGAGE  
Same as 20 and 25T with internal SPDT snap-  
switch for pre-alarm.  
For series A20T and A25T, the gage pointer acts as a  
temperature indicator and as one switch pole which  
completes a circuit when it touches the adjustable limit  
contact. Contact(s) are isolated from ground. They have  
self-cleaning motion to enhance electrical continuity.  
Cylinder Head Temperature  
®
A20TH and A25TH SWICHGAGE  
Limit Contact Adjustment: by a 1/16 in. hex  
wrench thru 100% of the scale.  
A20TH (was A20TL8133) and A25TH (was  
A25TL8133). For use on Air Cooled engines.  
Wiring: A20T: Number 4 screw terminals;  
A25T: Number 6 screw terminals.  
Models A20TE and A25TE have internal snap-acting  
Gage–Only Models  
Snap-Switch Rating (A20TE and A25TE):  
SPDT, 3 A@ 30 VDC inductive; 4 A @  
125 VAC inductive.  
®
SPDT switches.  
A20TG and A25TG MURPHYGAGE  
Gage-only models, without contacts  
Gage without contact(s).  
®
(MURPHYGAGE ) are also available.  
Wiring: A20TE: Number 4 screw terminals;  
A25TE: Number 6 screw terminals.  
*
For optional capillary lengths, engine adapters, sensing bulbs  
and range combinations, see Murphy bulletin T-8428B.  
Applications  
Unit Weight: A20 Series: 11.9 oz. (0.370 kg).  
Applications for A20 and A25 Series temperature  
**dPirroedcuticvtes 8c9o/v3e3r6ed/EbEyCthriesgbaurdllientginecleocmtrpolmyawgintehtiEcMC Council  
compatibility except as noted.  
A25 Series Models: 13.3 oz. (0.413 kg).  
®
SWICHGAGE instruments include: engines and  
Unit Dimensions: A20 Series: 4-3/4 x 4-3/4 x 3 in.  
(121 x 121 x 76 mm). A25 Series Models: 4-3/4 x  
4-3/4 x 2-3/4 in. (121 x 121 x 70 mm).  
equipment in Oil Field, Marine, Irrigation Construction  
,
and Trucking industries. Monitoring Engine Coolant  
temperature, Crankcase Oil, Transmission Oil.  
Base Models  
Specifications  
Coolant or Oil Temperature  
Dial: White on black; U.S.A. standard scale is dual  
scale °F/°C; others available.  
®
A20T and A25T Series SWICHGAGE  
For these models the gage pointer makes with an  
adjustable contact to complete a pilot-duty circuit.  
Bulletin AT-95026B page 1 of 4  
 
Magnetic Switch  
®
INDUCTIVE AND HIGH CURRENT LOADS REQUIRE THE USE OF A  
TATTLETALE Magnetic Switches show the cause of shutdown for applica-  
tions that include: capacitor discharge or magneto ignitions, battery systems and  
electric motor driven equipment. Typical wiring diagrams are shown below.  
®
MAGNETIC SWITCH. The SWICHGAGE contacts are for light-duty elec-  
trical switching to operate alarms or control devices. Murphy manufactures the  
®
Magnetic Switch for protection of the pilot-duty SWICHGAGE limit contacts.  
®
A20T Temperature  
SWICHGAGE®  
A20P Pressure  
518PH TATTLETALE  
117 Magnetic Switch  
SWICHGAGE®  
A20T Temperature  
SWICHGAGE®  
R
LOW  
N. C.  
HIGH  
G
NC  
SW1  
SW2  
B
HIGH  
C
S
B
®
N.O. SWICHGAGE  
instruments  
C
C
N. O.  
C
N. O.  
_
Energized To Run Devices  
+
Battery  
Energized To Run Devices  
_
+
Battery  
N.C. switches option  
Pre-Alarm Using A20/A25TABS  
The A20TABS and A25TABS features a standard limit contact for equipment  
shutdown on high temperature. It also has an internal SPDT snap-switch to sig-  
nal an alarm before shutting down. When the snap-switch trips (preset point), on  
and the shutdown circuit will be completed (see the typical diagram below for  
reference). The front contact shutdown limit setting (which is adjustable) and  
the snap-switch are preset at the factory. Refer to “Temperature Ranges and  
rising temperature, the switch completes a circuit to activate an alarm. If the Factory Settings” table on opposite page for settings. For alternative alarm  
temperature continues to increase, the face-adjustable pointer contact will make before shutdown, see Magnetic Switch model 760A or 761APH.  
Alarm Before  
Shutdown  
518PH  
A20TABS  
TATTLETALE®  
SWICHGAGE®  
MINI-SIREN®  
R
G
NC  
SW1  
SW2  
B
ABS  
N. C.  
HIGH  
N. O.  
C
Shutdown Device  
or Ignition Circuit  
Opens circuit to  
_
shutdown engine.  
+
Battery  
Typical Internal Wiring Diagrams  
Pointer shown in the shelf position. Pointer type contact rating: pilot-duty 2 A @ 30 VAC/VDC resistive.  
Snap-acting switch rating: 3 A @ 30 VDC inductive. 4 A @ 125 VAC inductive.  
A20T  
A20T-HL  
A20TABS  
A20TE  
HIGH  
N. O.  
LOW  
HIGH  
RESET  
ABS  
HIGH  
SET  
N. O.  
N. O.  
N. O.  
N. C.  
C
N. C.  
C
N. C.  
C
N. C.  
C
A25T  
A25TABS  
A25TABS-HL  
A25TE  
A25T-HL  
N. O.  
N. O.  
N. O.  
N. O.  
N. O.  
C
C
C
N. C.  
C
N. C.  
C
N. C.  
N. C.  
N. C.  
RESET  
SET  
RESET  
SET  
RESET  
SET  
HIGH  
LOW  
HIGH  
HIGH  
LOW  
HIGH  
H
L
P
H
H
H
H
P
P
P
L
L
L
L
P
Bulletin AT-95026B page 3 of 4  
 
How to Order  
To order, use the diagram below. List options in ascending alphabetical order (A-Z). Example: A20T-B1-250-4.  
____ – ____ – ____ – ____ – ____  
Base Model  
Adapter Nuts†††  
A20TG  
A25T  
A20T  
1/8 = 1/8-27 NPT  
1/4 = 1/4-18 NPT  
3/8 = 3/8-18 NPT  
3/8B = 3/8-19 BSPT  
3/8K = 3/8 NPSF  
Metric  
A20TL  
A20TO  
A20TE  
A20TABS  
A20TB  
A20TH  
M10 = 10 mm x 1.5  
M12 = 12 mm x 1.5  
M14 = 14 mm x 1.5  
M16 = 16 mm x 1.5  
M18 = 18 mm x 1.5  
M20 = 20 mm x 1.5  
M22 = 22 mm x 1.5  
M24 = 24 mm x 1.5  
A25TL  
A25TE  
A25TABS  
A25TH  
A25TG  
= 1/2-14 NPT††††  
1/2B = 1/2-BSPT  
1/2K = 1/2 NPSF  
5/8 = 5/8-18 UNF  
3/4 = 3/4-14 NPT  
3/4U = 3/4-16 UNF  
7/8 = 7/8-9 UNC  
†††  
Options†  
Specific adapter nut must  
match the sensing bulb.  
Standard.  
††††  
B1 = Black bezel  
EX = Explosion-proof (CSA Listed for  
Class I, Div. 1, Groups C & D)*  
EL = Explosion-proof less case  
HL = High and low contacts  
K = Knob adjusting face contact  
Temperature Capillary Armor Type  
and Length  
Capillary Armor Type  
Blank = PVC armor, copper capillary  
S = Stainless steel armor, copper capillary  
OS = Oil sealed (Silicone Oil)  
UA = Temperature bulb style “A” (10-05-0166)  
UB = Temperature bulb style “B” (10-01-0061)  
UC = Temperature bulb style “C” (10-01-0060)  
UD = Temperature bulb style “D” (10-00-0286)  
UE = Temperature bulb style “E” (10-01-0084)  
UF = Temperature bulb style “F” (10-00-0577)  
UG = Temperature bulb style “G” (10-00-0578)  
UH = Temperature bulb style “H” (10-00-2466)  
UJ = Temperature bulb style J (10051153)  
UK = Temperature bulb style K (10054886)  
Capillary Length (specify after capillary type;  
example: “S4”)  
4 = 4 ft. (1.2 m)  
Specify other length = Available in 2 ft. increments  
thru 20 ft.; 5 ft. increments above 20 ft. (0.5 m.  
increments from 1.5–10 m.; 2 m. increments thru  
34 m. Specify “M” following length, i.e. 1.5M.)  
Range††  
Dual scale (°F/°C)  
Single scale (°C)  
°F  
°C  
*
70C = 0-70°C  
Options not available on all models or configurations.  
A25TE-EX only is CSA listed for hazardous locations.  
120 = 32-120  
160 = 32-160  
0-49  
0-71  
100C = 45-100°C  
120C = 50-120°C  
140C = 60-140°C  
160C = 70-160°C  
**  
This option is not covered by the CE mark.  
220 = 130-220 54-104  
250 = 130-250 60-121  
300 = 140-300 60-149  
320 = 160-320 71-160  
350 = 180-350 82-177  
440 = 300-440 149-227  
Illumination – Order Separately  
A20 Series: Clamp Lite Assembly; 12 V= 05702176; 24 V= 05702177  
A25 Series: N/A.  
††  
Consult factory for availability of dials other than °F/°C. Select scale  
so your normal operating temperature is in the upper half of the scale.  
Warranty  
A limited warranty on materials and workmanship is given with  
this FW Murphy product. A copy of the warranty may be viewed  
CONTROL SYSTEMS & SERVICES DIVISION  
FRANK W. MURPHY, LTD.  
Church Rd.; Laverstock, Salisbury SP1 1QZ; U.K.  
+44 1722 410055 fax +44 1722 410088  
P.O. Box 1819; Rosenberg, Texas 77471; USA  
+1 281 633 4500 fax +1 281 633 4588  
FW Murphy  
INDUSTRIAL PANEL DIVISION  
P.O. Box 470248  
Tulsa, Oklahoma 74147 USA  
+1 918 317 4100 fax +1 918 317 4266  
P.O. Box 470248  
MURPHY DE MEXICO, S.A. DE C.V.  
Blvd. Antonio Rocha Cordero 300, Fracción del Aguaje  
San Luis Potosí, S.L.P.; México 78384  
+52 444 8206264 fax +52 444 8206336  
Villahermosa Office +52 993 3162117  
Tulsa, Oklahoma 74147 USA  
+1 918 317 4100 fax +1 918 317 4266  
www.fwmurphy.com  
Printed in U.S.A.  
In order to consistently bring you the highest quality, full featured products, we reserve the right to change our specifications and designs at any time.  
Bulletin AT-95026B page 4 of 4  
 

Miele Ventilation Hood 10 093 470 User Manual
Multiquip Portable Generator DCA70US13CAN User Manual
NEC Answering Machine AD 64 User Manual
NETGEAR Network Router PR2000 User Manual
Panasonic Camcorder AG AC130P User Manual
Panasonic CRT Television CT 20SL13 CT 24SL13 CT 27SL13 CT F2123 CT F2123L CT F2523 CT F2523L CT F2523X CT F2923 CT F2923L CT F2923X User Manual
Panasonic Electric Shaver ES2262 User Manual
Panasonic Mixer AW PH405N User Manual
Panasonic Smoke Alarm 1826 User Manual
Parker Hannifin Automobile OEMZL4 User Manual